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Brot S, Auger C, Bentata R, Rogemond V, Ménigoz S, Chounlamountri N, Girard-Egrot A, Honnorat J, Moradi-Améli M. Collapsin response mediator protein 5 (CRMP5) induces mitophagy, thereby regulating mitochondrion numbers in dendrites. J Biol Chem 2013; 289:2261-76. [PMID: 24324268 DOI: 10.1074/jbc.m113.490862] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Degradation of damaged mitochondria by mitophagy is an essential process to ensure cell homeostasis. Because neurons, which have a high energy demand, are particularly dependent on the mitochondrial dynamics, mitophagy represents a key mechanism to ensure correct neuronal function. Collapsin response mediator proteins 5 (CRMP5) belongs to a family of cytosolic proteins involved in axon guidance and neurite outgrowth signaling during neural development. CRMP5, which is highly expressed during brain development, plays an important role in the regulation of neuronal polarity by inhibiting dendrite outgrowth at early developmental stages. Here, we demonstrated that CRMP5 was present in vivo in brain mitochondria and is targeted to the inner mitochondrial membrane. The mitochondrial localization of CRMP5 induced mitophagy. CRMP5 overexpression triggered a drastic change in mitochondrial morphology, increased the number of lysosomes and double membrane vesicles termed autophagosomes, and enhanced the occurrence of microtubule-associated protein 1 light chain 3 (LC3) at the mitochondrial level. Moreover, the lipidated form of LC3, LC3-II, which triggers autophagy by insertion into autophagosomes, enhanced mitophagy initiation. Lysosomal marker translocates at the mitochondrial level, suggesting autophagosome-lysosome fusion, and induced the reduction of mitochondrial content via lysosomal degradation. We show that during early developmental stages the strong expression of endogenous CRMP5, which inhibits dendrite growth, correlated with a decrease of mitochondrial content. In contrast, the knockdown or a decrease of CRMP5 expression at later stages enhanced mitochondrion numbers in cultured neurons, suggesting that CRMP5 modulated these numbers. Our study elucidates a novel regulatory mechanism that utilizes CRMP5-induced mitophagy to orchestrate proper dendrite outgrowth and neuronal function.
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102
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Alcocer-Gómez E, Cano-García FJ, Cordero MD. Effect of coenzyme Q10 evaluated by 1990 and 2010 ACR Diagnostic Criteria for Fibromyalgia and SCL-90-R: Four case reports and literature review. Nutrition 2013; 29:1422-5. [DOI: 10.1016/j.nut.2013.05.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2013] [Revised: 04/15/2013] [Accepted: 05/12/2013] [Indexed: 01/07/2023]
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103
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Wu SB, Wu YT, Wu TP, Wei YH. Role of AMPK-mediated adaptive responses in human cells with mitochondrial dysfunction to oxidative stress. Biochim Biophys Acta Gen Subj 2013; 1840:1331-44. [PMID: 24513455 DOI: 10.1016/j.bbagen.2013.10.034] [Citation(s) in RCA: 122] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Revised: 10/06/2013] [Accepted: 10/22/2013] [Indexed: 02/09/2023]
Abstract
BACKGROUND Mitochondrial DNA (mtDNA) mutations are an important cause of mitochondrial diseases, for which there is no effective treatment due to complex pathophysiology. It has been suggested that mitochondrial dysfunction-elicited reactive oxygen species (ROS) plays a vital role in the pathogenesis of mitochondrial diseases, and the expression levels of several clusters of genes are altered in response to the elevated oxidative stress. Recently, we reported that glycolysis in affected cells with mitochondrial dysfunction is upregulated by AMP-activated protein kinase (AMPK), and such an adaptive response of metabolic reprogramming plays an important role in the pathophysiology of mitochondrial diseases. SCOPE OF REVIEW We summarize recent findings regarding the role of AMPK-mediated signaling pathways that are involved in: (1) metabolic reprogramming, (2) alteration of cellular redox status and antioxidant enzyme expression, (3) mitochondrial biogenesis, and (4) autophagy, a master regulator of mitochondrial quality control in skin fibroblasts from patients with mitochondrial diseases. MAJOR CONCLUSION Induction of adaptive responses via AMPK-PFK2, AMPK-FOXO3a, AMPK-PGC-1α, and AMPK-mTOR signaling pathways, respectively is modulated for the survival of human cells under oxidative stress induced by mitochondrial dysfunction. We suggest that AMPK may be a potential target for the development of therapeutic agents for the treatment of mitochondrial diseases. GENERAL SIGNIFICANCE Elucidation of the adaptive mechanism involved in AMPK activation cascades would lead us to gain a deeper insight into the crosstalk between mitochondria and the nucleus in affected tissue cells from patients with mitochondrial diseases. This article is part of a Special Issue entitled Frontiers of Mitochondrial Research.
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Affiliation(s)
- Shi-Bei Wu
- Institute of Biochemistry and Molecular Biology, National Yang-Ming University, Taipei 112, Taiwan
| | - Yu-Ting Wu
- Institute of Biochemistry and Molecular Biology, National Yang-Ming University, Taipei 112, Taiwan
| | - Tsung-Pu Wu
- Institute of Biochemistry and Molecular Biology, National Yang-Ming University, Taipei 112, Taiwan
| | - Yau-Huei Wei
- Institute of Biochemistry and Molecular Biology, National Yang-Ming University, Taipei 112, Taiwan; Department of Medicine, Mackay Medical College, New Taipei City 252, Taiwan.
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104
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Wang Y, Hekimi S. Mitochondrial respiration without ubiquinone biosynthesis. Hum Mol Genet 2013; 22:4768-83. [PMID: 23847050 DOI: 10.1093/hmg/ddt330] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Ubiquinone (UQ), a.k.a. coenzyme Q, is a redox-active lipid that participates in several cellular processes, in particular mitochondrial electron transport. Primary UQ deficiency is a rare but severely debilitating condition. Mclk1 (a.k.a. Coq7) encodes a conserved mitochondrial enzyme that is necessary for UQ biosynthesis. We engineered conditional Mclk1 knockout models to study pathogenic effects of UQ deficiency and to assess potential therapeutic agents for the treatment of UQ deficiencies. We found that Mclk1 knockout cells are viable in the total absence of UQ. The UQ biosynthetic precursor DMQ9 accumulates in these cells and can sustain mitochondrial respiration, albeit inefficiently. We demonstrated that efficient rescue of the respiratory deficiency in UQ-deficient cells by UQ analogues is side chain length dependent, and that classical UQ analogues with alkyl side chains such as idebenone and decylUQ are inefficient in comparison with analogues with isoprenoid side chains. Furthermore, Vitamin K2, which has an isoprenoid side chain, and has been proposed to be a mitochondrial electron carrier, had no efficacy on UQ-deficient mouse cells. In our model with liver-specific loss of Mclk1, a large depletion of UQ in hepatocytes caused only a mild impairment of respiratory chain function and no gross abnormalities. In conjunction with previous findings, this surprisingly small effect of UQ depletion indicates a nonlinear dependence of mitochondrial respiratory capacity on UQ content. With this model, we also showed that diet-derived UQ10 is able to functionally rescue the electron transport deficit due to severe endogenous UQ deficiency in the liver, an organ capable of absorbing exogenous UQ.
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Affiliation(s)
- Ying Wang
- Department of Biology, McGill University, Montréal, Quebec, Canada H3A 1B1
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105
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Coenzyme Q10 depletion in medical and neuropsychiatric disorders: potential repercussions and therapeutic implications. Mol Neurobiol 2013; 48:883-903. [PMID: 23761046 DOI: 10.1007/s12035-013-8477-8] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2013] [Accepted: 05/29/2013] [Indexed: 12/18/2022]
Abstract
Coenzyme Q10 (CoQ10) is an antioxidant, a membrane stabilizer, and a vital cofactor in the mitochondrial electron transport chain, enabling the generation of adenosine triphosphate. It additionally regulates gene expression and apoptosis; is an essential cofactor of uncoupling proteins; and has anti-inflammatory, redox modulatory, and neuroprotective effects. This paper reviews the known physiological role of CoQ10 in cellular metabolism, cell death, differentiation and gene regulation, and examines the potential repercussions of CoQ10 depletion including its role in illnesses such as Parkinson's disease, depression, myalgic encephalomyelitis/chronic fatigue syndrome, and fibromyalgia. CoQ10 depletion may play a role in the pathophysiology of these disorders by modulating cellular processes including hydrogen peroxide formation, gene regulation, cytoprotection, bioenegetic performance, and regulation of cellular metabolism. CoQ10 treatment improves quality of life in patients with Parkinson's disease and may play a role in delaying the progression of that disorder. Administration of CoQ10 has antidepressive effects. CoQ10 treatment significantly reduces fatigue and improves ergonomic performance during exercise and thus may have potential in alleviating the exercise intolerance and exhaustion displayed by people with myalgic encepholamyletis/chronic fatigue syndrome. Administration of CoQ10 improves hyperalgesia and quality of life in patients with fibromyalgia. The evidence base for the effectiveness of treatment with CoQ10 may be explained via its ability to ameliorate oxidative stress and protect mitochondria.
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106
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Ding WX, Yin XM. Mitophagy: mechanisms, pathophysiological roles, and analysis. Biol Chem 2013; 393:547-64. [PMID: 22944659 DOI: 10.1515/hsz-2012-0119] [Citation(s) in RCA: 698] [Impact Index Per Article: 63.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2012] [Accepted: 04/07/2012] [Indexed: 12/14/2022]
Abstract
Abstract Mitochondria are essential organelles that regulate cellular energy homeostasis and cell death. The removal of damaged mitochondria through autophagy, a process called mitophagy, is thus critical for maintaining proper cellular functions. Indeed, mitophagy has been recently proposed to play critical roles in terminal differentiation of red blood cells, paternal mitochondrial degradation, neurodegenerative diseases, and ischemia or drug-induced tissue injury. Removal of damaged mitochondria through autophagy requires two steps: induction of general autophagy and priming of damaged mitochondria for selective autophagic recognition. Recent progress in mitophagy studies reveals that mitochondrial priming is mediated either by the Pink1-Parkin signaling pathway or the mitophagic receptors Nix and Bnip3. In this review, we summarize our current knowledge on the mechanisms of mitophagy. We also discuss the pathophysiological roles of mitophagy and current assays used to monitor mitophagy.
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Affiliation(s)
- Wen-Xing Ding
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160, USA.
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107
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Jose C, Melser S, Benard G, Rossignol R. Mitoplasticity: adaptation biology of the mitochondrion to the cellular redox state in physiology and carcinogenesis. Antioxid Redox Signal 2013; 18:808-49. [PMID: 22989324 DOI: 10.1089/ars.2011.4357] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Adaptation and transformation biology of the mitochondrion to redox status is an emerging domain of physiology and pathophysiology. Mitochondrial adaptations occur in response to accidental changes in cellular energy demand or supply while mitochondrial transformations are a part of greater program of cell metamorphosis. The possible role of mitochondrial adaptations and transformations in pathogenesis remains unexplored, and it has become critical to decipher the stimuli and the underlying molecular pathways. Immediate activation of mitochondrial function was described during acute exercise, respiratory chain injury, Endoplasmic Reticulum stress, genotoxic stress, or environmental toxic insults. Delayed adaptations of mitochondrial form, composition, and functions were evidenced for persistent changes in redox status as observed in endurance training, in fibroblasts grown in presence of respiratory chain inhibitors or in absence of glucose, in the smooth muscle of patients with severe asthma, or in the skeletal muscle of patients with a mitochondrial disease. Besides, mitochondrial transformations were observed in the course of human cell differentiation, during immune response activation, or in cells undergoing carcinogenesis. Little is known on the signals and downstream pathways that govern mitochondrial adaptations and transformations. Few adaptative loops, including redox sensors, kinases, and transcription factors were deciphered, but their implication in physiology and pathology remains elusive. Mitoplasticity could play a protective role against aging, diabetes, cancer, or neurodegenerative diseases. Research on adaptation and transformation could allow the design of innovative therapies, notably in cancer.
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Affiliation(s)
- Caroline Jose
- University Bordeaux, Maladies Rares: Génétique et Métabolisme, France
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108
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Bess AS, Ryde IT, Hinton DE, Meyer JN. UVC-induced mitochondrial degradation via autophagy correlates with mtDNA damage removal in primary human fibroblasts. J Biochem Mol Toxicol 2013; 27:28-41. [PMID: 23132756 PMCID: PMC3640456 DOI: 10.1002/jbt.21440] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2012] [Accepted: 09/08/2012] [Indexed: 11/07/2022]
Abstract
Mitochondrial DNA (mtDNA) is more susceptible than nuclear DNA to helix-distorting damage via exposure to environmental genotoxins, partially due to a lack of nucleotide excision repair. Thus, this damage is irreparable and persistent in mtDNA in the short term. We recently found that helix-distorting mtDNA damage induced by ultraviolet C radiation (UVC) is gradually removed in Caenorhabditis elegans and that removal is dependent upon autophagy and mitochondrial dynamics. We here report the effects of UVC exposure on mitophagy, mitochondrial morphology, and indicators of mitochondrial function in mammalian cells. Exposure to UVC induced autophagy within 24 h; nonetheless, significant mitochondrial degradation was not observed until 72 h post exposure. Mitochondrial mass, morphology, and function were not significantly altered. These data further support the idea that persistent mtDNA damage is removed by autophagy and also suggest a powerful compensatory capacity for dealing with mtDNA damage.
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Affiliation(s)
- Amanda S Bess
- Nicholas School of the Environment, Integrated Toxicology and Environmental Health Program, Duke University, Research Drive, Durham, NC 27708, USA
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109
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Duberley KEC, Abramov AY, Chalasani A, Heales SJ, Rahman S, Hargreaves IP. Human neuronal coenzyme Q10 deficiency results in global loss of mitochondrial respiratory chain activity, increased mitochondrial oxidative stress and reversal of ATP synthase activity: implications for pathogenesis and treatment. J Inherit Metab Dis 2013; 36:63-73. [PMID: 22767283 DOI: 10.1007/s10545-012-9511-0] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Revised: 06/11/2012] [Accepted: 06/14/2012] [Indexed: 01/13/2023]
Abstract
Disorders of coenzyme Q(10) (CoQ(10)) biosynthesis represent the most treatable subgroup of mitochondrial diseases. Neurological involvement is frequently observed in CoQ(10) deficiency, typically presenting as cerebellar ataxia and/or seizures. The aetiology of the neurological presentation of CoQ(10) deficiency has yet to be fully elucidated and therefore in order to investigate these phenomena we have established a neuronal cell model of CoQ(10) deficiency by treatment of neuronal SH-SY5Y cell line with para-aminobenzoic acid (PABA). PABA is a competitive inhibitor of the CoQ(10) biosynthetic pathway enzyme, COQ2. PABA treatment (1 mM) resulted in a 54 % decrease (46 % residual CoQ(10)) decrease in neuronal CoQ(10) status (p < 0.01). Reduction of neuronal CoQ(10) status was accompanied by a progressive decrease in mitochondrial respiratory chain enzyme activities, with a 67.5 % decrease in cellular ATP production at 46 % residual CoQ(10). Mitochondrial oxidative stress increased four-fold at 77 % and 46 % residual CoQ(10). A 40 % increase in mitochondrial membrane potential was detected at 46 % residual CoQ(10) with depolarisation following oligomycin treatment suggesting a reversal of complex V activity. This neuronal cell model provides insights into the effects of CoQ(10) deficiency on neuronal mitochondrial function and oxidative stress, and will be an important tool to evaluate candidate therapies for neurological conditions associated with CoQ(10) deficiency.
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Affiliation(s)
- Kate E C Duberley
- Department of Molecular Neuroscience, UCL Institute of Neurology and Neurometabolic Unit, National Hospital for Neurology, Queen Square, London WC1N 3BG, UK.
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110
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García-Corzo L, Luna-Sánchez M, Doerrier C, García JA, Guarás A, Acín-Pérez R, Bullejos-Peregrín J, López A, Escames G, Enríquez JA, Acuña-Castroviejo D, López LC. Dysfunctional Coq9 protein causes predominant encephalomyopathy associated with CoQ deficiency. Hum Mol Genet 2012; 22:1233-48. [PMID: 23255162 DOI: 10.1093/hmg/dds530] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Coenzyme Q10 (CoQ(10)) or ubiquinone is a well-known component of the mitochondrial respiratory chain. In humans, CoQ(10) deficiency causes a mitochondrial syndrome with an unexplained variability in the clinical presentations. To try to understand this heterogeneity in the clinical phenotypes, we have generated a Coq9 Knockin (R239X) mouse model. The lack of a functional Coq9 protein in homozygous Coq9 mutant (Coq9(X/X)) mice causes a severe reduction in the Coq7 protein and, as consequence, a widespread CoQ deficiency and accumulation of demethoxyubiquinone. The deficit in CoQ induces a brain-specific impairment of mitochondrial bioenergetics performance, a reduction in respiratory control ratio, ATP levels and ATP/ADP ratio and specific loss of respiratory complex I. These effects lead to neuronal death and demyelinization with severe vacuolization and astrogliosis in the brain of Coq9(X/X) mice that consequently die between 3 and 6 months of age. These results suggest that the instability of mitochondrial complex I in the brain, as a primary event, triggers the development of mitochondrial encephalomyopathy associated with CoQ deficiency.
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Affiliation(s)
- Laura García-Corzo
- Instituto de Biotecnologı´a, Centro de Investigacio´n Biome´dica, Parque Tecnolo´gico de Ciencias de la Salud, Armilla, Granada, Spain
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111
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Deffieu M, Bhatia-Kiššová I, Salin B, Klionsky DJ, Pinson B, Manon S, Camougrand N. Increased levels of reduced cytochrome b and mitophagy components are required to trigger nonspecific autophagy following induced mitochondrial dysfunction. J Cell Sci 2012; 126:415-26. [PMID: 23230142 DOI: 10.1242/jcs.103713] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Mitochondria are essential organelles producing most of the energy required for the cell. A selective autophagic process called mitophagy removes damaged mitochondria, which is critical for proper cellular homeostasis; dysfunctional mitochondria can generate excess reactive oxygen species that can further damage the organelle as well as other cellular components. Although proper cell physiology requires the maintenance of a healthy pool of mitochondria, little is known about the mechanism underlying the recognition and selection of damaged organelles. In this study, we investigated the cellular fate of mitochondria damaged by the action of respiratory inhibitors (antimycin A, myxothiazol, KCN) that act on mitochondrial respiratory complexes III and IV, but have different effects with regard to the production of reactive oxygen species and increased levels of reduced cytochromes. Antimycin A and potassium cyanide effectively induced nonspecific autophagy, but not mitophagy, in a wild-type strain of Saccharomyces cerevisiae; however, low or no autophagic activity was measured in strains deficient for genes that encode proteins involved in mitophagy, including ATG32, ATG11 and BCK1. These results provide evidence for a major role of specific mitophagy factors in the control of a general autophagic cellular response induced by mitochondrial alteration. Moreover, increased levels of reduced cytochrome b, one of the components of the respiratory chain, could be the first signal of this induction pathway.
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Affiliation(s)
- Maika Deffieu
- CNRS, IBGC, UMR5095, 1 rue Camille Saint-Saëns, F-33000 Bordeaux, France
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112
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Abstract
Ubiquinone (UQ), also known as coenzyme Q (CoQ), is a redox-active lipid present in all cellular membranes where it functions in a variety of cellular processes. The best known functions of UQ are to act as a mobile electron carrier in the mitochondrial respiratory chain and to serve as a lipid soluble antioxidant in cellular membranes. All eukaryotic cells synthesize their own UQ. Most of the current knowledge on the UQ biosynthetic pathway was obtained by studying Escherichia coli and Saccharomyces cerevisiae UQ-deficient mutants. The orthologues of all the genes known from yeast studies to be involved in UQ biosynthesis have subsequently been found in higher organisms. Animal mutants with different genetic defects in UQ biosynthesis display very different phenotypes, despite the fact that in all these mutants the same biosynthetic pathway is affected. This review summarizes the present knowledge of the eukaryotic biosynthesis of UQ, with focus on the biosynthetic genes identified in animals, including Caenorhabditis elegans, rodents, and humans. Moreover, we review the phenotypes of mutants in these genes and discuss the functional consequences of UQ deficiency in general.
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Affiliation(s)
- Ying Wang
- Department of Biology, McGill University, Montréal, Quebec, Canada
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113
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Quinzii CM, Garone C, Emmanuele V, Tadesse S, Krishna S, Dorado B, Hirano M. Tissue-specific oxidative stress and loss of mitochondria in CoQ-deficient Pdss2 mutant mice. FASEB J 2012; 27:612-21. [PMID: 23150520 DOI: 10.1096/fj.12-209361] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Primary human CoQ(10) deficiencies are clinically heterogeneous diseases caused by mutations in PDSS2 and other genes required for CoQ(10) biosynthesis. Our in vitro studies of PDSS2 mutant fibroblasts, with <20% CoQ(10) of control cells, revealed reduced activity of CoQ(10)-dependent complex II+III and ATP synthesis, without amplification of reactive oxygen species (ROS), markers of oxidative damage, or antioxidant defenses. In contrast, COQ2 and ADCK3 mutant fibroblasts, with 30-50% CoQ(10) of controls, showed milder bioenergetic defects but significantly increased ROS and oxidation of lipids and proteins. We hypothesized that absence of oxidative stress markers and cell death in PDSS2 mutant fibroblasts were due to the extreme severity of CoQ(10) deficiency. Here, we have investigated in vivo effects of Pdss2 deficiency in affected and unaffected organs of CBA/Pdss2(kd/kd) mice at presymptomatic, phenotypic-onset, and end-stages of the disease. Although Pdss2 mutant mice manifest widespread CoQ(9) deficiency and mitochondrial respiratory chain abnormalities, only affected organs show increased ROS production, oxidative stress, mitochondrial DNA depletion, and reduced citrate synthase activity, an index of mitochondrial mass. Our data indicate that kidney-specific loss of mitochondria triggered by oxidative stress may be the cause of renal failure in Pdss2(kd/kd) mice.
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Affiliation(s)
- Catarina M Quinzii
- Department of Neurology, Columbia University Medical Center, New York, New York 10032, USA
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114
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Bullon P, Cordero MD, Quiles JL, Ramirez-Tortosa MDC, Gonzalez-Alonso A, Alfonsi S, García-Marín R, de Miguel M, Battino M. Autophagy in periodontitis patients and gingival fibroblasts: unraveling the link between chronic diseases and inflammation. BMC Med 2012; 10:122. [PMID: 23075094 PMCID: PMC3523085 DOI: 10.1186/1741-7015-10-122] [Citation(s) in RCA: 103] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Accepted: 10/17/2012] [Indexed: 12/01/2022] Open
Abstract
BACKGROUND Periodontitis, the most prevalent chronic inflammatory disease, has been related to cardiovascular diseases. Autophagy provides a mechanism for the turnover of cellular organelles and proteins through a lysosome-dependent degradation pathway. The aim of this research was to study the role of autophagy in peripheral blood mononuclear cells from patients with periodontitis and gingival fibroblasts treated with a lipopolysaccharide of Porphyromonas gingivalis. Autophagy-dependent mechanisms have been proposed in the pathogenesis of inflammatory disorders and in other diseases related to periodontitis, such as cardiovascular disease and diabetes. Thus it is important to study the role of autophagy in the pathophysiology of periodontitis. METHODS Peripheral blood mononuclear cells from patients with periodontitis (n = 38) and without periodontitis (n = 20) were used to study autophagy. To investigate the mechanism of autophagy, we evaluated the influence of a lipopolysaccharide from P. gingivalis in human gingival fibroblasts, and autophagy was monitored morphologically and biochemically. Autophagosomes were observed by immunofluorescence and electron microscopy. RESULTS We found increased levels of autophagy gene expression and high levels of mitochondrial reactive oxygen species production in peripheral blood mononuclear cells from patients with periodontitis compared with controls. A significantly positive correlation between both was observed. In human gingival fibroblasts treated with lipopolysaccharide from P. gingivalis, there was an increase of protein and transcript of autophagy-related protein 12 (ATG12) and microtubule-associated protein 1 light chain 3 alpha LC3. A reduction of mitochondrial reactive oxygen species induced a decrease in autophagy whereas inhibition of autophagy in infected cells increased apoptosis, showing the protective role of autophagy. CONCLUSION Results from the present study suggest that autophagy is an important and shared mechanism in other conditions related to inflammation or alterations of the immune system, such as periodontitis.
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Affiliation(s)
- Pedro Bullon
- Dipartimento di Scienze Cliniche Specialistiche ed Odontostomatologiche - Sezione Biochimica, Università Politecnica delle Marche, Via Ranieri, 65, Ancona, 60100, Italia
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115
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Frank M, Duvezin-Caubet S, Koob S, Occhipinti A, Jagasia R, Petcherski A, Ruonala MO, Priault M, Salin B, Reichert AS. Mitophagy is triggered by mild oxidative stress in a mitochondrial fission dependent manner. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2012; 1823:2297-310. [PMID: 22917578 DOI: 10.1016/j.bbamcr.2012.08.007] [Citation(s) in RCA: 332] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 02/09/2012] [Revised: 08/06/2012] [Accepted: 08/07/2012] [Indexed: 12/16/2022]
Abstract
Mitochondrial dysfunction is linked to apoptosis, aging, cancer, and a number of neurodegenerative and muscular disorders. The interplay between mitophagy and mitochondrial dynamics has been linked to the removal of dysfunctional mitochondria ensuring mitochondrial quality control. An open question is what role mitochondrial fission plays in the removal of mitochondria after mild and transient oxidative stress; conditions reported to result in moderately elevated reactive oxygen species (ROS) levels comparable to physical activity. Here we show that applying such conditions led to fragmentation of mitochondria and induction of mitophagy in mouse and human cells. These conditions increased ROS levels only slightly and neither triggered cell death nor led to a detectable induction of non-selective autophagy. Starvation led to hyperfusion of mitochondria, to high ROS levels, and to the induction of both non-selective autophagy and to a lesser extent to mitophagy. We conclude that moderate levels of ROS specifically trigger mitophagy but are insufficient to trigger non-selective autophagy. Expression of a dominant-negative variant of the fission factor DRP1 blocked mitophagy induction by mild oxidative stress as well as by starvation. Taken together, we demonstrate that in mammalian cells under mild oxidative stress a DRP1-dependent type of mitophagy is triggered while a concomitant induction of non-selective autophagy was not observed. We propose that these mild oxidative conditions resembling well physiological situations are thus very helpful for studying the molecular pathways governing the selective removal of dysfunctional mitochondria.
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Affiliation(s)
- Magdalena Frank
- Adolf-Butenandt-Institut für Physiologische Chemie, Ludwig-Maximilians-Universität München, Germany
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116
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Bildirici I, Longtine MS, Chen B, Nelson DM. Survival by self-destruction: a role for autophagy in the placenta? Placenta 2012; 33:591-8. [PMID: 22652048 PMCID: PMC3389146 DOI: 10.1016/j.placenta.2012.04.011] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2012] [Revised: 04/17/2012] [Accepted: 04/17/2012] [Indexed: 12/20/2022]
Abstract
Autophagy is a burgeoning area of research from yeast to humans. Although previously described as a death pathway, autophagy is now considered an important survival phenomenon in response to environmental stressors to which most organs are exposed. Despite an ever expanding literature in non-placental cells, studies of autophagy in the placenta are lagging. We review the regulation of autophagy, summarize available placental studies of autophagy, and highlight potential areas for future research. We believe that such studies will yield novel insights into how placentas protect the survival of the species by "self-eating".
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Affiliation(s)
- I Bildirici
- Department of Obstetrics and Gynecology, Acibadem University School of Medicine, Istanbul, Turkey.
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117
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Bhatia-Kiššová I, Camougrand N. Mitophagy: a process that adapts to the cell physiology. Int J Biochem Cell Biol 2012; 45:30-3. [PMID: 22801005 DOI: 10.1016/j.biocel.2012.07.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Revised: 06/26/2012] [Accepted: 07/01/2012] [Indexed: 10/28/2022]
Abstract
This focus makes a case that mitophagy is not a straightforward process obeying simple rules. It is a complex process through which the cell gets rid of both damaged and healthy untainted mitochondria to adjust their amount, and in accordance with cellular energy requirements. Several aspects of mitophagy have been described in both yeast and mammalian cells. They have revealed a number of discrepancies in the regulation of this process in the two eukaryotic models. Data have shown that mitophagy is a function of cell physiology. This article is part of a Directed Issue entitled: Bioenergetic dysfunction, adaptation and therapy.
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Affiliation(s)
- Ingrid Bhatia-Kiššová
- Comenius University, Faculty of Natural Sciences, Department of Biochemistry, Mlynská dolina CH1, 84215 Bratislava, Slovak Republic
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118
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Bess AS, Crocker TL, Ryde IT, Meyer JN. Mitochondrial dynamics and autophagy aid in removal of persistent mitochondrial DNA damage in Caenorhabditis elegans. Nucleic Acids Res 2012; 40:7916-31. [PMID: 22718972 PMCID: PMC3439916 DOI: 10.1093/nar/gks532] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Mitochondria lack the ability to repair certain helix-distorting lesions that are induced at high levels in mitochondrial DNA (mtDNA) by important environmental genotoxins and endogenous metabolites. These lesions are irreparable and persistent in the short term, but their long-term fate is unknown. We report that removal of such mtDNA damage is detectable by 48 h in Caenorhabditis elegans, and requires mitochondrial fusion, fission and autophagy, providing genetic evidence for a novel mtDNA damage removal pathway. Furthermore, mutations in genes involved in these processes as well as pharmacological inhibition of autophagy exacerbated mtDNA damage-mediated larval arrest, illustrating the in vivo relevance of removal of persistent mtDNA damage. Mutations in genes in these pathways exist in the human population, demonstrating the potential for important gene-environment interactions affecting mitochondrial health after genotoxin exposure.
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Affiliation(s)
- Amanda S Bess
- Duke University, Nicholas School of Environment, Integrated Toxicology and Environmental Health Program, LSRC, PO Box 90328, Durham, NC 27708, USA
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119
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Oxidative stress: a pathogenic mechanism for Niemann-Pick type C disease. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2012; 2012:205713. [PMID: 22720116 PMCID: PMC3374944 DOI: 10.1155/2012/205713] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Revised: 04/04/2012] [Accepted: 04/05/2012] [Indexed: 01/01/2023]
Abstract
Niemann-Pick type C (NPC) disease is a neurovisceral atypical lipid storage disorder involving the accumulation of cholesterol and other lipids in the late endocytic pathway. The pathogenic mechanism that links the accumulation of intracellular cholesterol with cell death in NPC disease in both the CNS and the liver is currently unknown. Oxidative stress has been observed in the livers and brains of NPC mice and in different NPC cellular models. Moreover, there is evidence of an elevation of oxidative stress markers in the serumof NPC patients. Recent evidence strongly suggests that mitochondrial dysfunction plays an important role in NPC pathogenesis and that mitochondria could be a significant source of oxidative stress in this disease. In this context, the accumulation of vitamin E in the late endosomal/lysosomal compartments in NPC could lead to a potential decrease of its bioavailability and could be another possible cause of oxidative damage. Another possible source of reactive species in NPC is the diminished activity of different antioxidant enzymes. Moreover, because NPC is mainly caused by the accumulation of free cholesterol, oxidized cholesterol derivatives produced by oxidative stress may contribute to the pathogenesis of the disease.
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120
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Terracciano A, Renaldo F, Zanni G, D'Amico A, Pastore A, Barresi S, Valente EM, Piemonte F, Tozzi G, Carrozzo R, Valeriani M, Boldrini R, Mercuri E, Santorelli FM, Bertini E. The use of muscle biopsy in the diagnosis of undefined ataxia with cerebellar atrophy in children. Eur J Paediatr Neurol 2012; 16:248-56. [PMID: 21873089 PMCID: PMC3341568 DOI: 10.1016/j.ejpn.2011.07.016] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Revised: 07/21/2011] [Accepted: 07/24/2011] [Indexed: 01/07/2023]
Abstract
Childhood cerebellar ataxias, and particularly congenital ataxias, are heterogeneous disorders and several remain undefined. We performed a muscle biopsy in patients with congenital ataxia and children with later onset undefined ataxia having neuroimaging evidence of cerebellar atrophy. Significant reduced levels of Coenzyme Q10 (COQ10) were found in the skeletal muscle of 9 out of 34 patients that were consecutively screened. A mutation in the ADCK3/Coq8 gene (R347X) was identified in a female patient with ataxia, seizures and markedly reduced COQ10 levels. In a 2.5-years-old male patient with non syndromic congenital ataxia and autophagic vacuoles in the muscle biopsy we identified a homozygous nonsense mutation R111X mutation in SIL1 gene, leading to early diagnosis of Marinesco-Sjogren syndrome. We think that muscle biopsy is a valuable procedure to improve diagnostic assesement in children with congenital ataxia or other undefined forms of later onset childhood ataxia associated to cerebellar atrophy at MRI.
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Affiliation(s)
- Alessandra Terracciano
- Unit of Neuromuscular and Neurodegenerative Disorders, Lab of Molecular Medicine, Dept of Neuroscience, Bambino Gesù Childrens Hospital, Rome, Italy
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121
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Cordero MD, Cano-García FJ, Alcocer-Gómez E, De Miguel M, Sánchez-Alcázar JA. Oxidative stress correlates with headache symptoms in fibromyalgia: coenzyme Q₁₀ effect on clinical improvement. PLoS One 2012; 7:e35677. [PMID: 22532869 PMCID: PMC3330812 DOI: 10.1371/journal.pone.0035677] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2011] [Accepted: 03/21/2012] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND Fibromyalgia (FM) is a chronic pain syndrome with unknown etiology and a wide spectrum of symptoms such as allodynia, debilitating fatigue, joint stiffness and migraine. Recent studies have shown some evidences demonstrating that oxidative stress is associated to clinical symptoms in FM of fibromyalgia. We examined oxidative stress and bioenergetic status in blood mononuclear cells (BMCs) and its association to headache symptoms in FM patients. The effects of oral coenzyme Q(10) (CoQ(10)) supplementation on biochemical markers and clinical improvement were also evaluated. METHODS We studied 20 FM patients and 15 healthy controls. Clinical parameters were evaluated using the Fibromyalgia Impact Questionnaire (FIQ), visual analogues scales (VAS), and the Headache Impact Test (HIT-6). Oxidative stress was determined by measuring CoQ(10), catalase and lipid peroxidation (LPO) levels in BMCs. Bioenergetic status was assessed by measuring ATP levels in BMCs. RESULTS We found decreased CoQ(10), catalase and ATP levels in BMCs from FM patients as compared to normal control (P < 0.05 and P < 0.001, respectively) We also found increased level of LPO in BMCs from FM patients as compared to normal control (P < 0.001). Significant negative correlations between CoQ(10) or catalase levels in BMCs and headache parameters were observed (r = -0.59, P < 0.05; r = -0.68, P < 0.05, respectively). Furthermore, LPO levels showed a significant positive correlation with HIT-6 (r = 0.33, P<0.05). Oral CoQ(10) supplementation restored biochemical parameters and induced a significant improvement in clinical and headache symptoms (P < 0.001). DISCUSSION The results of this study suggest a role for mitochondrial dysfunction and oxidative stress in the headache symptoms associated with FM. CoQ10 supplementation should be examined in a larger placebo controlled trial as a possible treatment in FM.
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Affiliation(s)
- Mario D Cordero
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-CSIC-Junta de Andalucía and Centro de Investigación Biomédica en Red de Enfermedades Raras, ISCIII, Sevilla, Spain.
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122
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Implications of therapy-induced selective autophagy on tumor metabolism and survival. Int J Cell Biol 2012; 2012:872091. [PMID: 22550492 PMCID: PMC3328951 DOI: 10.1155/2012/872091] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Accepted: 01/14/2012] [Indexed: 01/13/2023] Open
Abstract
Accumulating evidence indicates that therapies designed to trigger apoptosis in tumor cells cause mitochondrial depolarization, nuclear damage, and the accumulation of misfolded protein aggregates, resulting in the activation of selective forms of autophagy. These selective forms of autophagy, including mitophagy, nucleophagy, and ubiquitin-mediated autophagy, counteract apoptotic signals by removing damaged cellular structures and by reprogramming cellular energy metabolism to cope with therapeutic stress. As a result, the efficacies of numerous current cancer therapies may be improved by combining them with adjuvant treatments that exploit or disrupt key metabolic processes induced by selective forms of autophagy. Targeting these metabolic irregularities represents a promising approach to improve clinical responsiveness to cancer treatments given the inherently elevated metabolic demands of many tumor types. To what extent anticancer treatments promote selective forms of autophagy and the degree to which they influence metabolism are currently under intense scrutiny. Understanding how the activation of selective forms of autophagy influences cellular metabolism and survival provides an opportunity to target metabolic irregularities induced by these pathways as a means of augmenting current approaches for treating cancer.
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123
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De la Mata M, Garrido-Maraver J, Cotán D, Cordero MD, Oropesa-Ávila M, Izquierdo LG, De Miguel M, Lorite JB, Infante ER, Ybot P, Jackson S, Sánchez-Alcázar JA. Recovery of MERRF fibroblasts and cybrids pathophysiology by coenzyme Q10. Neurotherapeutics 2012; 9:446-63. [PMID: 22354625 PMCID: PMC3337023 DOI: 10.1007/s13311-012-0103-3] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Mitochondrial DNA mutations are an important cause of human disease for which there is no effective treatment. Myoclonic epilepsy with ragged-red fibers (MERRF) is a mitochondrial disease usually caused by point mutations in transfer RNA genes encoded by mitochondrial DNA. The most common mutation associated with MERRF syndrome, m.8344A > G in the gene MT-TK, which encodes transfer RNA(Lysine), affects the translation of all mitochondrial DNA encoded proteins. This impairs the assembly of the electron transport chain complexes leading to decreased mitochondrial respiratory function. Here we report on how this mutation affects mitochondrial function in primary fibroblast cultures established from patients harboring the A8344G mutation. Coenzyme Q10 levels, as well as mitochondrial respiratory chain activity, and mitochondrial protein expression levels were significantly decreased in MERRF fibroblasts. Mitotracker staining and imaging analysis of individual mitochondria indicated the presence of small, rounded, depolarized mitochondria in MERRF fibroblasts. Mitochondrial dysfunction was associated with increased oxidative stress and increased degradation of impaired mitochondria by mitophagy. Transmitochondrial cybrids harboring the A8344G mutation also showed CoQ10 deficiency, mitochondrial dysfunction, and increased mitophagy activity. All these abnormalities in patient-derived fibroblasts and cybrids were partially restored by CoQ10 supplementation, indicating that these cell culture models may be suitable for screening and validation of novel drug candidates for MERRF disease.
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Affiliation(s)
- Mario De la Mata
- />Centro Andaluz de Biología del Desarrollo, CABD-CSIC-UPO-JA and Centro de Investigación Biomédica en Red: Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Universidad Pablo de Olavide-Consejo Superior de Investigaciones Científicas-Junta de Andalucía, Sevilla, 41013 Spain
| | - Juan Garrido-Maraver
- />Centro Andaluz de Biología del Desarrollo, CABD-CSIC-UPO-JA and Centro de Investigación Biomédica en Red: Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Universidad Pablo de Olavide-Consejo Superior de Investigaciones Científicas-Junta de Andalucía, Sevilla, 41013 Spain
| | - David Cotán
- />Centro Andaluz de Biología del Desarrollo, CABD-CSIC-UPO-JA and Centro de Investigación Biomédica en Red: Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Universidad Pablo de Olavide-Consejo Superior de Investigaciones Científicas-Junta de Andalucía, Sevilla, 41013 Spain
| | - Mario D. Cordero
- />Centro Andaluz de Biología del Desarrollo, CABD-CSIC-UPO-JA and Centro de Investigación Biomédica en Red: Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Universidad Pablo de Olavide-Consejo Superior de Investigaciones Científicas-Junta de Andalucía, Sevilla, 41013 Spain
| | - Manuel Oropesa-Ávila
- />Centro Andaluz de Biología del Desarrollo, CABD-CSIC-UPO-JA and Centro de Investigación Biomédica en Red: Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Universidad Pablo de Olavide-Consejo Superior de Investigaciones Científicas-Junta de Andalucía, Sevilla, 41013 Spain
| | | | - Manuel De Miguel
- />Departamento de Citología e Histología Normal y Patológica, Facultad de Medicina, Universidad de Sevilla, Sevilla, 41009 Spain
| | | | - Eloy Rivas Infante
- />Departamento de Anatomía Patológica, Hospital Virgen del Rocío, Sevilla, 41013 Spain
| | - Patricia Ybot
- />Instituto de Biomedicina de Sevilla (IBIS)-CSIC, Hospital Virgen del Rocío, Sevilla, 41013 Spain
| | | | - José A. Sánchez-Alcázar
- />Centro Andaluz de Biología del Desarrollo, CABD-CSIC-UPO-JA and Centro de Investigación Biomédica en Red: Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Universidad Pablo de Olavide-Consejo Superior de Investigaciones Científicas-Junta de Andalucía, Sevilla, 41013 Spain
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124
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Effects of inhibiting CoQ10 biosynthesis with 4-nitrobenzoate in human fibroblasts. PLoS One 2012; 7:e30606. [PMID: 22359546 PMCID: PMC3281033 DOI: 10.1371/journal.pone.0030606] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2011] [Accepted: 12/24/2011] [Indexed: 11/19/2022] Open
Abstract
Coenzyme Q10 (CoQ10) is a potent lipophilic antioxidant in cell membranes and a carrier of electrons in the mitochondrial respiratory chain. We previously characterized the effects of varying severities of CoQ10 deficiency on ROS production and mitochondrial bioenergetics in cells harboring genetic defects of CoQ10 biosynthesis. We observed a unimodal distribution of ROS production with CoQ10 deficiency: cells with <20% of CoQ10 and 50–70% of CoQ10 did not generate excess ROS while cells with 30–45% of CoQ10 showed increased ROS production and lipid peroxidation. Because our previous studies were limited to a small number of mutant cell lines with heterogeneous molecular defects, here, we treated 5 control and 2 mildly CoQ10 deficient fibroblasts with varying doses of 4-nitrobenzoate (4-NB), an analog of 4-hydroxybenzoate (4-HB) and inhibitor of 4-para-hydroxybenzoate:polyprenyl transferase (COQ2) to induce a range of CoQ10 deficiencies. Our results support the concept that the degree of CoQ10 deficiency in cells dictates the extent of ATP synthesis defects and ROS production and that 40–50% residual CoQ10 produces maximal oxidative stress and cell death.
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125
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Maes M, Fišar Z, Medina M, Scapagnini G, Nowak G, Berk M. New drug targets in depression: inflammatory, cell-mediated immune, oxidative and nitrosative stress, mitochondrial, antioxidant, and neuroprogressive pathways. And new drug candidates--Nrf2 activators and GSK-3 inhibitors. Inflammopharmacology 2012; 20:127-50. [PMID: 22271002 DOI: 10.1007/s10787-011-0111-7] [Citation(s) in RCA: 246] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Accepted: 12/15/2011] [Indexed: 02/07/2023]
Abstract
This paper reviews new drug targets in the treatment of depression and new drug candidates to treat depression. Depression is characterized by aberrations in six intertwined pathways: (1) inflammatory pathways as indicated by increased levels of proinflammatory cytokines, e.g. interleukin-1 (IL-1), IL-6, and tumour necrosis factor α. (2) Activation of cell-mediated immune pathways as indicated by an increased production of interferon γ and neopterin. (3) Increased reactive oxygen and nitrogen species and damage by oxidative and nitrosative stress (O&NS), including lipid peroxidation, damage to DNA, proteins and mitochondria. (4) Lowered levels of key antioxidants, such as coenzyme Q10, zinc, vitamin E, glutathione, and glutathione peroxidase. (5) Damage to mitochondria and mitochondrial DNA and reduced activity of respiratory chain enzymes and adenosine triphosphate production. (6) Neuroprogression, which is the progressive process of neurodegeneration, apoptosis, and reduced neurogenesis and neuronal plasticity, phenomena that are probably caused by inflammation and O&NS. Antidepressants tend to normalize the above six pathways. Targeting these pathways has the potential to yield antidepressant effects, e.g. using cytokine antagonists, minocycline, Cox-2 inhibitors, statins, acetylsalicylic acid, ketamine, ω3 poly-unsaturated fatty acids, antioxidants, and neurotrophic factors. These six pathways offer new, pathophysiologically guided drug targets suggesting that novel therapies could be developed that target these six pathways simultaneously. Both nuclear factor (erythroid-derived 2)-like 2 (Nrf2) activators and glycogen synthase kinase-3 (GSK-3) inhibitors target the six above-mentioned pathways. GSK-3 inhibitors have antidepressant effects in animal models of depression. Nrf2 activators and GSK-3 inhibitors have the potential to be advanced to phase-2 clinical trials to examine whether they augment the efficacy of antidepressants or are useful as monotherapy.
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Affiliation(s)
- Michael Maes
- Maes Clinics@TRIA, 998 Rimklongsamsen Road, Bangkok 10310, Thailand.
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126
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Hirano M, Garone C, Quinzii CM. CoQ(10) deficiencies and MNGIE: two treatable mitochondrial disorders. Biochim Biophys Acta Gen Subj 2012; 1820:625-31. [PMID: 22274133 DOI: 10.1016/j.bbagen.2012.01.006] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2011] [Revised: 12/28/2011] [Accepted: 01/10/2012] [Indexed: 12/25/2022]
Abstract
BACKGROUND Although causative mutations have been identified for numerous mitochondrial disorders, few disease-modifying treatments are available. Two examples of treatable mitochondrial disorders are coenzyme Q(10) (CoQ(10) or ubiquinone) deficiency and mitochondrial neurogastrointestinal encephalomyopathy (MNGIE). SCOPE OF REVIEW Here, we describe clinical and molecular features of CoQ(10) deficiencies and MNGIE and explain how understanding their pathomechanisms have led to rationale therapies. Primary CoQ(10) deficiencies, due to mutations in genes required for ubiquinone biosynthesis, and secondary deficiencies, caused by genetic defects not directly related to CoQ(10) biosynthesis, often improve with CoQ(10) supplementation. In vitro and in vivo studies of CoQ(10) deficiencies have revealed biochemical alterations that may account for phenotypic differences among patients and variable responses to therapy. In contrast to the heterogeneous CoQ(10) deficiencies, MNGIE is a single autosomal recessive disease due to mutations in the TYMP gene encoding thymidine phosphorylase (TP). In MNGIE, loss of TP activity causes toxic accumulations of the nucleosides thymidine and deoxyuridine that are incorporated by the mitochondrial pyrimidine salvage pathway and cause deoxynucleoside triphosphate pool imbalances, which, in turn cause mtDNA instability. Allogeneic hematopoetic stem cell transplantation to restore TP activity and eliminate toxic metabolites is a promising therapy for MNGIE. MAJOR CONCLUSIONS CoQ(10) deficiencies and MNGIE demonstrate the feasibility of treating specific mitochondrial disorders through replacement of deficient metabolites or via elimination of excessive toxic molecules. GENERAL SIGNIFICANCE Studies of CoQ(10) deficiencies and MNGIE illustrate how understanding the pathogenic mechanisms of mitochondrial diseases can lead to meaningful therapies. This article is part of a Special Issue entitled: Biochemistry of Mitochondria, Life and Intervention 2010.
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Affiliation(s)
- Michio Hirano
- Department of Neurology, Columbia University Medical Center, New York, NY 10032, USA
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127
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Abstract
PURPOSE OF REVIEW Coenzyme Q (CoQ) is a vital component of the mitochondrial respiratory chain. A number of patients with CoQ deficiency presented with different clinical phenotypes, often affecting skeletal muscle, and responded well to CoQ supplementation. We discuss recent advances in this field with special attention to muscle involvement. RECENT FINDINGS The identification of genetic defects causing CoQ deficiency has allowed to distinguish primary forms, due to mutations in biosynthetic genes, from secondary defects caused either by mutations in genes unrelated to CoQ biosynthesis or by nongenetic factors. To date, none of the patients with genetically proven primary deficiency presented with an exclusively (or prominently) myopathic phenotype. Most patients with myopathy were found to harbor other genetic defects (mutations in electron-transferring-flavoprotein dehydrogenase or mitochondrial DNA). The majority of patients with CoQ deficiency still lack a genetic diagnosis. The pathogenesis of CoQ deficiency cannot be attributed solely to the bioenergetic defect, suggesting that other roles of CoQ, including its antioxidant properties or its role in pyrimidine metabolism, may also play crucial roles. SUMMARY Early recognition of CoQ deficiency is essential to institute appropriate and timely treatment, thus avoiding irreversible tissue damage.
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128
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Tang PH, Miles MV. Measurement of oxidized and reduced coenzyme Q in biological fluids, cells, and tissues: an HPLC-EC method. Methods Mol Biol 2012; 837:149-168. [PMID: 22215546 DOI: 10.1007/978-1-61779-504-6_10] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Direct measure of coenzyme Q (CoQ) in biological specimens may provide important advantages. Precise and selective high-performance liquid chromatography (HPLC) methods with electrochemical (EC) detection have been developed for the measurement of reduced (ubiquinol) and oxidized (ubiquinone) CoQ in biological fluids, cells, and tissues. EC detection is preferred for measurement of CoQ because of its high sensitivity. Reduced and oxidized CoQ are first extracted from biological specimens using 1-propanol. After centrifugation, the 1-propanol supernatant is directly injected into HPLC and monitored at a dual-electrode. The EC reactions occur at the electrode surface. The first electrode transforms ubiquinone into ubiquinol, and the second electrode measures the current produced by the oxidation of the hydroquinone group of ubiquinol. The methods described provide rapid, precise, and simple procedures for determination of reduced and oxidized CoQ in biological fluids, cells, and tissues. The methods have been successfully adapted to meet regulatory requirements for clinical laboratories, and have been proven reliable for analysis of clinical and research samples for clinical trials and animal studies involving large numbers of specimens.
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Affiliation(s)
- Peter H Tang
- Division of Pathology and Laboratory Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
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129
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Quinzii CM, Hirano M. Primary and secondary CoQ(10) deficiencies in humans. Biofactors 2011; 37:361-5. [PMID: 21990098 PMCID: PMC3258494 DOI: 10.1002/biof.155] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2011] [Accepted: 03/09/2011] [Indexed: 11/06/2022]
Abstract
CoQ(10) deficiencies are clinically and genetically heterogeneous. This syndrome has been associated with five major clinical phenotypes: (1) encephalomyopathy, (2) severe infantile multisystemic disease, (3) cerebellar ataxia, (4) isolated myopathy, and (5) nephrotic syndrome. In a few patients, pathogenic mutations have been identified in genes involved in the biosynthesis of CoQ(10) (primary CoQ(10) deficiencies) or in genes not directly related to CoQ(10) biosynthesis (secondary CoQ(10) deficiencies). Respiratory chain defects, ROS production, and apoptosis variably contribute to the pathogenesis of primary CoQ(10) deficiencies.
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Affiliation(s)
| | - Michio Hirano
- Address for correspondence: Dr. Michio Hirano, MD, Department of Neurology, Columbia University Medical Center, 630 West 168th Street, P&S 4-423, New York, NY 10032, USA.
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130
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Green DR, Galluzzi L, Kroemer G. Mitochondria and the autophagy-inflammation-cell death axis in organismal aging. Science 2011; 333:1109-12. [PMID: 21868666 PMCID: PMC3405151 DOI: 10.1126/science.1201940] [Citation(s) in RCA: 860] [Impact Index Per Article: 66.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Alterations of mitochondrial functions are linked to multiple degenerative or acute diseases. As mitochondria age in our cells, they become progressively inefficient and potentially toxic, and acute damage can trigger the permeabilization of mitochondrial membranes to initiate apoptosis or necrosis. Moreover, mitochondria have an important role in pro-inflammatory signaling. Autophagic turnover of cellular constituents, be it general or specific for mitochondria (mitophagy), eliminates dysfunctional or damaged mitochondria, thus counteracting degeneration, dampening inflammation, and preventing unwarranted cell loss. Decreased expression of genes that regulate autophagy or mitophagy can cause degenerative diseases in which deficient quality control results in inflammation and the death of cell populations. Thus, a combination of mitochondrial dysfunction and insufficient autophagy may contribute to multiple aging-associated pathologies.
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Affiliation(s)
- Douglas R. Green
- Department of Immunology, St Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Lorenzo Galluzzi
- INSERM, U848, F-94805 Villejuif, France
- Institut Gustave Roussy, F94805 Villejuif, France
- Université Paris-Sud, Paris 11, F-94805 Villejuif, France
| | - Guido Kroemer
- INSERM, U848, F-94805 Villejuif, France
- Metabolomics Platform, Institut Gustave Roussy, F-94805 Villejuif, France
- Centre de Recherche des Cordeliers, F-75005 Paris, France
- Pôle de Biologie, Hôpital Européen Georges Pompidou, AP-HP, F-75908 Paris, France
- Université Paris Descartes, Paris 5, F-75270 Paris, France
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131
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Cerebellar defects in Pdss2 conditional knockout mice during embryonic development and in adulthood. Neurobiol Dis 2011; 45:219-33. [PMID: 21871565 DOI: 10.1016/j.nbd.2011.08.006] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2011] [Revised: 07/22/2011] [Accepted: 08/03/2011] [Indexed: 01/31/2023] Open
Abstract
PDSS2 is a gene that encodes one of the two subunits of trans-prenyl diphosphate synthase that is essential for ubiquinone biosynthesis. It is known that mutations in PDSS2 can cause primary ubiquinone deficiency in humans and a similar disease in mice. Cerebellum is the most often affected organ in ubiquinone deficiency, and cerebellar atrophy has been diagnosed in many infants with this disease. In this study, two Pdss2 conditional knockout mouse lines directed by Pax2-cre and Pcp2-cre were generated to investigate the effect of ubiquinone deficiency on cerebellum during embryonic development and in adulthood, respectively. The Pdss2(f/-); Pax2-cre mouse recapitulates some symptoms of ubiquinone deficiency in infants, including severe cerebellum hypoplasia and lipid accumulation in skeletal muscles at birth. During early cerebellum development (E12.5-14.5), Pdss2 knockout initially causes the delay of radial glial cell growth and neuron progenitor migration, so the growth of mutant cerebellum is retarded. During later development (E15.5-P0), increased ectopic apoptosis of neuroblasts and impaired cell proliferation result in the progression of cerebellum hypoplasia in the mutant. Thus, the mutant cerebellum contains fewer neurons at birth, and the cells are disorganized. The developmental defect of mutant cerebellum does not result from reduced Fgf8 expression before E12.5. Electron microscopy reveals mitochondrial defects and increased autophagic-like vacuolization that may arise in response to abnormal mitochondria in the mutant cerebellum. Nevertheless, the mutant mice die soon after birth probably due to cleft palate and micrognathia, which may result from Pdss2 knockout caused by ectopic Pax2-cre expression in the first branchial arch. On the other hand, the Pdss2(f/-); Pcp2-cre mouse is healthy at birth but gradually loses cerebellar Purkinje cells and develops ataxia-like symptoms at 9.5 months; thus this conditional knockout mouse may serve as a model for ubiquinone deficiency in adult patients. In conclusion, this study provides two mouse models of Pdss2 based ubiquinone deficiency. During cerebellum development, Pdss2 knockout results in severe cerebellum hypoplasia by impairing cell migration and eliciting ectopic apoptosis, whereas Pdss2 knockout in Purkinje cells at postnatal stages leads to the development of cerebellar ataxia.
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Krzywanski DM, Moellering DR, Fetterman JL, Dunham-Snary KJ, Sammy MJ, Ballinger SW. The mitochondrial paradigm for cardiovascular disease susceptibility and cellular function: a complementary concept to Mendelian genetics. J Transl Med 2011; 91:1122-35. [PMID: 21647091 PMCID: PMC3654682 DOI: 10.1038/labinvest.2011.95] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
While there is general agreement that cardiovascular disease (CVD) development is influenced by a combination of genetic, environmental, and behavioral contributors, the actual mechanistic basis of how these factors initiate or promote CVD development in some individuals while others with identical risk profiles do not, is not clearly understood. This review considers the potential role for mitochondrial genetics and function in determining CVD susceptibility from the standpoint that the original features that molded cellular function were based upon mitochondrial-nuclear relationships established millions of years ago and were likely refined during prehistoric environmental selection events that today, are largely absent. Consequently, contemporary risk factors that influence our susceptibility to a variety of age-related diseases, including CVD were probably not part of the dynamics that defined the processes of mitochondrial-nuclear interaction, and thus, cell function. In this regard, the selective conditions that contributed to cellular functionality and evolution should be given more consideration when interpreting and designing experimental data and strategies. Finally, future studies that probe beyond epidemiologic associations are required. These studies will serve as the initial steps for addressing the provocative concept that contemporary human disease susceptibility is the result of selection events for mitochondrial function that increased chances for prehistoric human survival and reproductive success.
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Affiliation(s)
- David M Krzywanski
- Division of Molecular and Cellular Pathology, Department of Pathology, The University of Alabama at Birmingham, Birmingham, AL, USA
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133
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Emma F, Montini G, Salviati L, Dionisi-Vici C. Renal mitochondrial cytopathies. Int J Nephrol 2011; 2011:609213. [PMID: 21811680 PMCID: PMC3146993 DOI: 10.4061/2011/609213] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2011] [Accepted: 06/03/2011] [Indexed: 11/20/2022] Open
Abstract
Renal diseases in mitochondrial cytopathies are a group of rare diseases that are characterized by frequent multisystemic involvement and extreme variability of phenotype. Most frequently patients present a tubular defect that is consistent with complete De Toni-Debré-Fanconi syndrome in most severe forms. More rarely, patients present with chronic tubulointerstitial nephritis, cystic renal diseases, or primary glomerular involvement. In recent years, two clearly defined entities, namely 3243 A > G tRNA(LEU) mutations and coenzyme Q10 biosynthesis defects, have been described. The latter group is particularly important because it represents the only treatable renal mitochondrial defect. In this paper, the physiopathologic bases of mitochondrial cytopathies, the diagnostic approaches, and main characteristics of related renal diseases are summarized.
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Affiliation(s)
- Francesco Emma
- Division of Nephrology and Dialysis, Department of Nephrology and Urology, Bambino Gesù Children's Hospital and Research Institute, piazza Sant'Onofrio 4, 00165 Rome, Italy
| | - Giovanni Montini
- Nephrology and Dialysis Unit, Pediatric Department, Azienda Ospedaliera di Bologna, 40138 Bologna, Italy
| | - Leonardo Salviati
- Clinical Genetics Unit, Department of Pediatrics, University of Padova, 35128 Padova, Italy
| | - Carlo Dionisi-Vici
- Division of Metabolic Diseases, Department of Pediatric Medicine, Bambino Gesù Children's Hospital and Research Institute, 00165 Rome, Italy
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134
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Geng T, Li P, Yin X, Yan Z. PGC-1α promotes nitric oxide antioxidant defenses and inhibits FOXO signaling against cardiac cachexia in mice. THE AMERICAN JOURNAL OF PATHOLOGY 2011; 178:1738-48. [PMID: 21435455 DOI: 10.1016/j.ajpath.2011.01.005] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2010] [Revised: 12/03/2010] [Accepted: 01/04/2011] [Indexed: 12/21/2022]
Abstract
Chronic heart failure often results in catabolic muscle wasting, exercise intolerance, and death. Oxidative muscles, which have greater expression of the metabolic master gene peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) and its target genes, are more resistant to catabolic wasting than are glycolytic muscles; however, the underlying mechanism is unknown. To determine the functional role of PGC-1α in oxidative phenotype-associated protection, skeletal muscle-specific PGC-1α transgenic mice were crossbred with cardiac-specific calsequestrin transgenic mice, a genetic model of chronic heart failure. PGC-1α overexpression in glycolytic muscles significantly attenuated catabolic muscle wasting induced by chronic heart failure. In addition to inactivation of forkhead transcription factor signaling through enhanced Akt/protein kinase B expression, in glycolytic muscles, PGC-1α overexpression led to enhanced expression of inducible nitric oxide synthase and endothelial nitric oxide synthase, production of nitric oxide, and expression of antioxidant enzyme including superoxide dismutases (SOD1, SOD2, and SOD3) and catalase, and reduced oxidative stress. These findings suggest that PGC-1α protects muscle from catabolic wasting in chronic heart failure through enhanced nitric oxide antioxidant defenses and inhibition of the forkhead transcription factor signaling pathways.
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Affiliation(s)
- Tuoyu Geng
- Department of Medicine-Cardiovascular Medicine, University of Virginia, Charlottesville, VA 22908, USA
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135
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Yang YY, Vasta V, Hahn S, Gangoiti JA, Opheim E, Sedensky MM, Morgan PG. The role of DMQ(9) in the long-lived mutant clk-1. Mech Ageing Dev 2011; 132:331-9. [PMID: 21745495 DOI: 10.1016/j.mad.2011.06.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2010] [Revised: 06/03/2011] [Accepted: 06/23/2011] [Indexed: 12/20/2022]
Abstract
INTRODUCTION Ubiquinone (UQ) is a redox active lipid that transfers electrons from complex I or II to complex III in the electron transport chain (ETC). The long-lived Caenorhabditis elegans mutant clk-1 is unable to synthesize its native ubiquinone, and accumulates high amounts of its precursor, 5-demethoxyubiquinone-9 (DMQ(9)). In clk-1, complexes I-III activity is inhibited while complexes II-III activity is normal. We asked whether the complexes I-III defect in clk-1 was caused by: (1) a defect in the ETC; (2) an inhibitory effect of DMQ(9); or (3) a decreased amount of ubiquinone. METHODS We extracted the endogenous quinones from wildtype (N2) and clk-1 mitochondria, replenished them with exogenous ubiquinones, and measured ETC activities. RESULTS Replenishment of extracted mutant and wildtype mitochondria resulted in equal enzymatic activities for complexes I-III and II-III ETC assays. Blue native gels showed that supercomplex formation was indistinguishable between clk-1 and N2. The addition of a pentane extract from clk-1 mitochondria containing DMQ(9) to wildtype mitochondria specifically inhibited complexes I-III activity. UQ in clk-1 mitochondria was oxidized compared to N2. DISCUSSION Our results show that no measurable intrinsic ETC defect exists in clk-1 mitochondria. The data indicate that DMQ(9) specifically inhibits electron transfer from complex I to ubiquinone.
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Affiliation(s)
- Yu-Ying Yang
- Department of Genetics, Case Western Reserve University, Cleveland, OH, United States.
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136
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Rahman S, Clarke CF, Hirano M. 176th ENMC International Workshop: diagnosis and treatment of coenzyme Q₁₀ deficiency. Neuromuscul Disord 2011; 22:76-86. [PMID: 21723727 DOI: 10.1016/j.nmd.2011.05.001] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2011] [Accepted: 04/27/2011] [Indexed: 10/18/2022]
Affiliation(s)
- Shamima Rahman
- Clinical and Molecular Genetics Unit, UCL Institute of Child Health, London WC1N 1EH, UK.
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137
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Cotán D, Cordero MD, Garrido-Maraver J, Oropesa-Ávila M, Rodríguez-Hernández A, Gómez Izquierdo L, De la Mata M, De Miguel M, Lorite JB, Infante ER, Jackson S, Navas P, Sánchez-Alcázar JA. Secondary coenzyme Q10 deficiency triggers mitochondria degradation by mitophagy in MELAS fibroblasts. FASEB J 2011; 25:2669-87. [PMID: 21551238 DOI: 10.1096/fj.10-165340] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) is a mitochondrial disease most usually caused by point mutations in tRNA genes encoded by mtDNA. Here, we report on how this mutation affects mitochondrial function in primary fibroblast cultures established from 2 patients with MELAS who harbored the A3243G mutation. Both mitochondrial respiratory chain enzyme activities and coenzyme Q(10) (CoQ) levels were significantly decreased in MELAS fibroblasts. A similar decrease in mitochondrial membrane potential was found in intact MELAS fibroblasts. Mitochondrial dysfunction was associated with increased oxidative stress and the activation of mitochondrial permeability transition (MPT), which triggered the degradation of impaired mitochondria. Furthermore, we found defective autophagosome elimination in MELAS fibroblasts. Electron and fluorescence microscopy studies confirmed a massive degradation of mitochondria and accumulation of autophagosomes, suggesting mitophagy activation and deficient autophagic flux. Transmitochondrial cybrids harboring the A3243G mutation also showed CoQ deficiency and increased autophagy activity. All these abnormalities were partially restored by CoQ supplementation. Autophagy in MELAS fibroblasts was also abolished by treatment with antioxidants or cyclosporine, suggesting that both reactive oxygen species and MPT participate in this process. Furthermore, prevention of autophagy in MELAS fibroblasts resulted in apoptotic cell death, suggesting a protective role of autophagy in MELAS fibroblasts.
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Affiliation(s)
- David Cotán
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-Consejo Superior de Investigaciones Científicas, Sevilla 41013, Spain
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138
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Goebel HH, Bönnemann CG. 169th ENMC International Workshop Rare Structural Congenital Myopathies 6-8 November 2009, Naarden, The Netherlands. Neuromuscul Disord 2011; 21:363-74. [PMID: 21414784 DOI: 10.1016/j.nmd.2011.02.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/08/2011] [Indexed: 11/26/2022]
Affiliation(s)
- Hans H Goebel
- University Medical Center of the Johannes Gutenberg University Mainz, Langenbeckstrasse 1, 55131 Mainz, Germany.
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139
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Zanchetta LM, Garcia A, Lyng F, Walsh J, Murphy JEJ. Mitophagy and mitochondrial morphology in human melanoma-derived cells post exposure to simulated sunlight. Int J Radiat Biol 2011; 87:506-17. [PMID: 21381890 DOI: 10.3109/09553002.2011.556175] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
PURPOSE To assess changes in mitochondrial morphology and mitophagy induced by simulated sunlight irradiation (SSI) and how these changes are modulated by mitochondrial activity and energy source. MATERIALS AND METHODS Human malignant amelanotic melanoma A375 cells were pre-treated with either a mitochondrial activity enhancer, uncoupler or were either melanin or glutamine supplemented/starved for 4 hours pre-exposure to sunlight. A Q-Sun Solar Simulator (Q-Lab, Homestead, FL, USA) was employed to expose cells to simulated sunlight. Confocal microscopy imaging of A375 cells co-loaded with mitochondria and lysosome-specific fluorescent dyes was used to identify these organelles and predict mitophagic events. RESULTS SSI induces pronounced changes in mitochondrial dynamics and mitophagy in exposed skin cells compared to control and these effects were modified by both glutamine and melanin. CONCLUSIONS Mitochondrial dynamics and rate of mitophagy in melanoma cells are sensitive to even short bursts of environmentally relevant SSI. Mitochondrial dynamics, and its modulation, may also play a role in mitophagy regulation, cell survival and proliferation post SSI.
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Affiliation(s)
- Luciene M Zanchetta
- Mitochondrial Biology & Radiation Research, School of Science, Institute of Technology Sligo, Ash Lane, Sligo, Ireland.
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140
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Quinsay MN, Thomas RL, Lee Y, Gustafsson AB. Bnip3-mediated mitochondrial autophagy is independent of the mitochondrial permeability transition pore. Autophagy 2011; 6:855-62. [PMID: 20668412 DOI: 10.4161/auto.6.7.13005] [Citation(s) in RCA: 174] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Bnip3 is a pro-apoptotic BH3-only protein which is associated with mitochondrial dysfunction and cell death. Bnip3 is also a potent inducer of autophagy in many cells. In this study, we have investigated the mechanism by which Bnip3 induces autophagy in adult cardiac myocytes. Overexpression of Bnip3 induced extensive autophagy in adult cardiac myocytes. Fluorescent microscopy studies and ultrastructural analysis revealed selective degradation of mitochondria by autophagy in myocytes overexpressing Bnip3. Oxidative stress and increased levels of intracellular Ca(2+) have been reported by others to induce autophagy, but Bnip3-induced autophagy was not abolished by antioxidant treatment or the Ca(2+) chelator BAPT A-AM. We also investigated the role of the mitochondrial permeability transition pore (mPTP) in Bnip3-induced autophagy. Although the mPTP has previously been implicated in the induction of autophagy and selective removal of damaged mitochondria by autophagosomes, mitochondria sequestered by autophagosomes in Bnip3-treated cardiac myocytes had not undergone permeability transition and treatment with the mPTP inhibitor cyclosporine A did not inhibit mitochondrial autophagy in cardiac myocytes. Moreover, cyclophilin D (cypD) is an essential component of the mPTP and Bnip3 induced autophagy to the same extent in embryonic fibroblasts isolated from wild-type and cypD-deficient mice. These results support a model where Bnip3 induces selective removal of the mitochondria in cardiac myocytes and that Bnip3 triggers induction of autophagy independent of Ca(2+), ROS generation, and mPTP opening.
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Affiliation(s)
- Melissa N Quinsay
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA, USA
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141
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Abstract
Mitochondria are essential for oxidative energy production in aerobic eukaryotic cells, where they are also required for multiple biosynthetic pathways to take place. Mitochondria also monitor and evaluate complex information from the environment and intracellular milieu, including the presence or absence of growth factors, oxygen, reactive oxygen species, and DNA damage. It follows that disturbances of the integrity of mitochondrial function lead to the disruption of cell function, expressed as disease, aging, or cell death. It has been assumed that the degradation of damaged mitochondria by an autophagy-related pathway specific to mitochondria (mitophagy), recently found to be strictly regulated, is a fundamental process essential for cell homeostasis. Until now, the main role of mitophagy has been tentatively defined as a 'house-cleaning' pathway that allows to eliminate altered mitochondria, but mitophagy may also play a role in the adaptation of the number and quality of mitochondria to new environmental conditions. In yeast, recent data defined two categories of mitophagy actors: ones constitutively required for mitophagy and those with mitophagy-regulatory functions. Situations were also uncovered in normal physiology in which cells utilize mitophagy to eliminate damaged, dysfunctional, and superfluous mitochondria to adjust to changing physiological demands.
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142
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Abstract
Coenzyme Q(10) (CoQ(10)) is an essential electron carrier in the mitochondrial respiratory chain and an important antioxidant. Deficiency of CoQ(10) is a clinically and molecularly heterogeneous syndrome, which, to date, has been found to be autosomal recessive in inheritance and generally responsive to CoQ(10) supplementation. CoQ(10) deficiency has been associated with five major clinical phenotypes: (1) encephalomyopathy, (2) severe infantile multisystemic disease, (3) cerebellar ataxia, (4) isolated myopathy, and (5) nephrotic syndrome. In a few patients, pathogenic mutations have been identified in genes involved in the biosynthesis of CoQ(10) (primary CoQ(10) deficiencies) or in genes not directly related to CoQ(10) biosynthesis (secondary CoQ(10) deficiencies). Respiratory chain defects, ROS production, and apoptosis contribute to the pathogenesis of primary CoQ(10) deficiencies. In vitro and in vivo studies are necessary to further understand the pathogenesis of the disease and to develop more effective therapies.
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Affiliation(s)
- Catarina M Quinzii
- Department of Neurology, Columbia University Medical Center, 630 West 168th Street, New York, NY 10032, USA
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143
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Prevention of diabetic nephropathy in Ins2(+/)⁻(AkitaJ) mice by the mitochondria-targeted therapy MitoQ. Biochem J 2010; 432:9-19. [PMID: 20825366 PMCID: PMC2973231 DOI: 10.1042/bj20100308] [Citation(s) in RCA: 165] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Mitochondrial production of ROS (reactive oxygen species) is thought to be associated with the cellular damage resulting from chronic exposure to high glucose in long-term diabetic patients. We hypothesized that a mitochondria-targeted antioxidant would prevent kidney damage in the Ins2(+/)⁻(AkitaJ) mouse model (Akita mice) of Type 1 diabetes. To test this we orally administered a mitochondria-targeted ubiquinone (MitoQ) over a 12-week period and assessed tubular and glomerular function. Fibrosis and pro-fibrotic signalling pathways were determined by immunohistochemical analysis, and mitochondria were isolated from the kidney for functional assessment. MitoQ treatment improved tubular and glomerular function in the Ins2(+/)⁻(AkitaJ) mice. MitoQ did not have a significant effect on plasma creatinine levels, but decreased urinary albumin levels to the same level as non-diabetic controls. Consistent with previous studies, renal mitochondrial function showed no significant change between any of the diabetic or wild-type groups. Importantly, interstitial fibrosis and glomerular damage were significantly reduced in the treated animals. The pro-fibrotic transcription factors phospho-Smad2/3 and β-catenin showed a nuclear accumulation in the Ins2(+/)⁻(AkitaJ) mice, which was prevented by MitoQ treatment. These results support the hypothesis that mitochondrially targeted therapies may be beneficial in the treatment of diabetic nephropathy. They also highlight a relatively unexplored aspect of mitochondrial ROS signalling in the control of fibrosis.
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144
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Miles MV, Putnam PE, Miles L, Tang PH, DeGrauw AJ, Wong BL, Horn PS, Foote HL, Rothenberg ME. Acquired coenzyme Q10 deficiency in children with recurrent food intolerance and allergies. Mitochondrion 2010; 11:127-35. [PMID: 20817046 DOI: 10.1016/j.mito.2010.08.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2010] [Revised: 08/06/2010] [Accepted: 08/24/2010] [Indexed: 11/28/2022]
Abstract
The current study evaluated 23 children (ages 2-16 years) with recurrent food intolerance and allergies for CoQ10 deficiency and mitochondrial abnormalities. Muscle biopsies were tested for CoQ10 levels, pathology, and mitochondrial respiratory chain (MRC) activities. Group 2 (age >10 years; n = 9) subjects had significantly decreased muscle CoQ10 than Group 1 (age <10 y; n = 14) subjects (p = 0.001) and 16 controls (p<0.05). MRC activities were significantly lower in Group 2 than in Group 1 (p<0.05). Muscle CoQ10 levels in study subjects were significantly correlated with duration of illness (adjusted r(2) = 0.69; p = 0.012; n = 23). Children with recurrent food intolerance and allergies may acquire CoQ10 deficiency with disease progression.
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Affiliation(s)
- Michael V Miles
- Division of Pathology and Laboratory Medicine, Department of Pediatrics, Cincinnati Children's Hospital Medical Center and University of Cincinnati College of Medicine, ML 2015, 3333 Burnet Ave, Cincinnati, OH 45229-3039, USA.
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145
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Santos RX, Correia SC, Wang X, Perry G, Smith MA, Moreira PI, Zhu X. A synergistic dysfunction of mitochondrial fission/fusion dynamics and mitophagy in Alzheimer's disease. J Alzheimers Dis 2010; 20 Suppl 2:S401-12. [PMID: 20463393 DOI: 10.3233/jad-2010-100666] [Citation(s) in RCA: 118] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Alzheimer's disease (AD), the most common form of dementia in the elderly, can have a late-onset sporadic or an early-onset familial origin. In both cases, the neuropathological hallmarks are the same: senile plaques and neurofibrillary tangles. Despite AD having a proteinopathic nature, there is strong evidence for an organelle dysfunction-related neuropathology, namely dysfunctional mitochondria. In this regard, dysfunctional mitochondria and associated exacerbated generation of reactive oxygen species are among the earliest events in the progression of the disease. Since the maintenance of a healthy mitochondrial pool is essential given the central role of this organelle in several determinant cellular processes, mitochondrial dysfunction in AD would be predicted to have profound pluripotent deleterious consequences. Mechanistically, recent reports suggest that mitochondrial fission/fusion and mitophagy are altered in AD and in in vitro models of disease, and since both processes are reported to be protective, this review will discuss the role of mitochondrial fission/fusion and mitophagy in the pathogenesis of AD.
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Affiliation(s)
- Renato X Santos
- Center for Neuroscience and Cell Biology of Coimbra, University of Coimbra, Coimbra, Portugal
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146
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Cordero MD, Moreno-Fernández AM, Carmona-López MI, Sánchez-Alcázar JA, Rodríguez AF, Navas P, de Miguel M. Mitochondrial dysfunction in skin biopsies and blood mononuclear cells from two cases of fibromyalgia patients. Clin Biochem 2010; 43:1174-6. [DOI: 10.1016/j.clinbiochem.2010.06.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2010] [Revised: 06/13/2010] [Accepted: 06/21/2010] [Indexed: 01/09/2023]
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147
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López LC, Quinzii CM, Area E, Naini A, Rahman S, Schuelke M, Salviati L, DiMauro S, Hirano M. Treatment of CoQ(10) deficient fibroblasts with ubiquinone, CoQ analogs, and vitamin C: time- and compound-dependent effects. PLoS One 2010; 5:e11897. [PMID: 20689595 PMCID: PMC2912846 DOI: 10.1371/journal.pone.0011897] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2010] [Accepted: 06/30/2010] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Coenzyme Q(10) (CoQ(10)) and its analogs are used therapeutically by virtue of their functions as electron carriers, antioxidant compounds, or both. However, published studies suggest that different ubiquinone analogs may produce divergent effects on oxidative phosphorylation and oxidative stress. METHODOLOGY/PRINCIPAL FINDINGS To test these concepts, we have evaluated the effects of CoQ(10), coenzyme Q(2) (CoQ(2)), idebenone, and vitamin C on bioenergetics and oxidative stress in human skin fibroblasts with primary CoQ(10) deficiency. A final concentration of 5 microM of each compound was chosen to approximate the plasma concentration of CoQ(10) of patients treated with oral ubiquinone. CoQ(10) supplementation for one week but not for 24 hours doubled ATP levels and ATP/ADP ratio in CoQ(10) deficient fibroblasts therein normalizing the bioenergetics status of the cells. Other compounds did not affect cellular bioenergetics. In COQ2 mutant fibroblasts, increased superoxide anion production and oxidative stress-induced cell death were normalized by all supplements. CONCLUSIONS/SIGNIFICANCE THESE RESULTS INDICATE THAT: 1) pharmacokinetics of CoQ(10) in reaching the mitochondrial respiratory chain is delayed; 2) short-tail ubiquinone analogs cannot replace CoQ(10) in the mitochondrial respiratory chain under conditions of CoQ(10) deficiency; and 3) oxidative stress and cell death can be counteracted by administration of lipophilic or hydrophilic antioxidants. The results of our in vitro experiments suggest that primary CoQ(10) deficiencies should be treated with CoQ(10) supplementation but not with short-tail ubiquinone analogs, such as idebenone or CoQ(2). Complementary administration of antioxidants with high bioavailability should be considered if oxidative stress is present.
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Affiliation(s)
- Luis C. López
- Department of Neurology, Columbia University Medical Center, New York, New York, United States of America
| | - Catarina M. Quinzii
- Department of Neurology, Columbia University Medical Center, New York, New York, United States of America
| | - Estela Area
- Department of Neurology, Columbia University Medical Center, New York, New York, United States of America
| | - Ali Naini
- Department of Neurology, Columbia University Medical Center, New York, New York, United States of America
| | - Shamima Rahman
- Clinical and Molecular Genetics Unit, University College London Institute of Child Health, London, United Kingdom
| | - Markus Schuelke
- Department of Neuropediatrics, Charité Virchow University Hospital, Berlin, Germany
| | - Leonardo Salviati
- Servizio di Genetica Clinica ed Epidemiologica, Department of Pediatrics, University of Padova, Padova, Italy
| | - Salvatore DiMauro
- Department of Neurology, Columbia University Medical Center, New York, New York, United States of America
| | - Michio Hirano
- Department of Neurology, Columbia University Medical Center, New York, New York, United States of America
- * E-mail:
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148
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Horbinski C, Mojesky C, Kyprianou N. Live free or die: tales of homeless (cells) in cancer. THE AMERICAN JOURNAL OF PATHOLOGY 2010; 177:1044-52. [PMID: 20639456 DOI: 10.2353/ajpath.2010.091270] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Anoikis, programed cell death that occurs on cell detachment from the extracellular matrix, thus disrupting integrin-ligand interactions, is a critical mechanism in preventing ectopic cell growth or attachment to an inappropriate matrix. Anoikis prevents shed epithelial cells from colonizing elsewhere and is thus essential for maintaining tissue organization. Lack of integrin ligation leads to decreased focal adhesion kinase and integrin-linked kinase activity, which impairs downstream survival signaling. Consequently, targeting tumor cell survival by triggering anoikis provides a unique molecular basis for novel therapeutic targeting of tumors before initiation of metastasis. The two major cell death pathways involved in anoikis signaling are apoptosis and autophagy; growing evidence suggests an extensive cross-talk between the two killing modes as well as context-dependent cooperation and antagonism. This review discusses the functional integration between the two modes of cell death converging at anoikis, including key molecules of interaction such as Beclin 1, reactive oxygen species, extracellular signal-related kinase, and death-associated protein kinase. The involvement of other apoptotic effectors such as Bcl-2, p53, and FLICE inhibitory protein in cancer cell anoikis is also discussed. Dissecting the mechanistic players in the cellular response may be of high clinical significance in identifying effective approaches in reversing anoikis resistance in primary tumor cells and, consequently, impairing metastasis.
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Affiliation(s)
- Craig Horbinski
- Department of Pathology, University of Kentucky, Lexington, Kentucky, USA
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149
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Menon GK, Dal Farra C, Botto JM, Domloge N. Mitochondria: a new focus as an anti-aging target in skin care. J Cosmet Dermatol 2010; 9:122-31. [DOI: 10.1111/j.1473-2165.2010.00496.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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150
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Quinzii CM, López LC, Gilkerson RW, Dorado B, Coku J, Naini AB, Lagier-Tourenne C, Schuelke M, Salviati L, Carrozzo R, Santorelli F, Rahman S, Tazir M, Koenig M, DiMauro S, Hirano M. Reactive oxygen species, oxidative stress, and cell death correlate with level of CoQ10 deficiency. FASEB J 2010; 24:3733-43. [PMID: 20495179 DOI: 10.1096/fj.09-152728] [Citation(s) in RCA: 122] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Coenzyme Q(10) (CoQ(10)) is essential for electron transport in the mitochondrial respiratory chain and antioxidant defense. The relative importance of respiratory chain defects, ROS production, and apoptosis in the pathogenesis of CoQ(10) deficiency is unknown. We determined previously that severe CoQ(10) deficiency in cultured skin fibroblasts harboring COQ2 and PDSS2 mutations produces divergent alterations of bioenergetics and oxidative stress. Here, to better understand the pathogenesis of CoQ(10) deficiency, we have characterized the effects of varying severities of CoQ(10) deficiency on ROS production and mitochondrial bioenergetics in cells harboring genetic defects of CoQ(10) biosynthesis. Levels of CoQ(10) seem to correlate with ROS production; 10-15% and >60% residual CoQ(10) are not associated with significant ROS production, whereas 30-50% residual CoQ(10) is accompanied by increased ROS production and cell death. Our results confirm that varying degrees of CoQ(10) deficiency cause variable defects of ATP synthesis and oxidative stress. These findings may lead to more rational therapeutic strategies for CoQ(10) deficiency.
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Affiliation(s)
- Catarina M Quinzii
- Department of Neurology, Columbia University Medical Center, 630 W. 168th St., P&S 4-423, New York, NY 10032, USA
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